Sign in →

Test ID: FDP Familial Dysautonomia, Mutation Analysis, IVS20(+6T>C) and R696P, Varies

Useful For

Carrier screening for familial dysautonomia in individuals of Ashkenazi Jewish ancestry


 Prenatal diagnosis of familial dysautonomia in at-risk pregnancies


Confirmation of a clinical diagnosis of familial dysautonomia in individuals of Ashkenazi Jewish ancestry

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
CULFB Fibroblast Culture for Genetic Test Yes No
CULAF Amniotic Fluid Culture/Genetic Test Yes No
MATCC Maternal Cell Contamination, B Yes No

Testing Algorithm

For prenatal specimens only: If amniotic fluid (nonconfluent cultured cells) is received, amniotic fluid culture will be added at an additional charge. If a chorionic villus specimen (nonconfluent cultured cells) is received, a fibroblast culture will be added at an additional charge. For any prenatal specimen that is received, maternal cell contamination studies will be added.

Method Name

Polymerase Chain Reaction (PCR)/Targeted Sanger Sequencing

Reporting Name

Familial Dysautonomia, Mutation

Specimen Type


Additional Testing Requirements

All prenatal specimens must be accompanied by a maternal blood specimen.

-Order MATCC / Maternal Cell Contamination, Molecular Analysis, Varies on the maternal specimen.

Shipping Instructions

Specimen preferred to arrive within 96 hours of collection.

Specimen Required

Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. Call 800-533-1710 for instructions for testing patients who have received a bone marrow transplant.


Submit only 1 of the following specimens:


Specimen Type: Whole blood


Preferred: Lavender top (EDTA) or yellow top (ACD)

Acceptable: Any anticoagulant

Specimen Volume: 2.6 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send specimen in original tube. Do not aliquot.

Specimen Stability Information: Ambient (preferred) 4 days/Refrigerated/Frozen


Prenatal Specimens

Due to the complexity of prenatal testing, consultation with the laboratory is required for all prenatal testing


Specimen Type: Amniotic fluid

Container/Tube: Amniotic fluid container

 Specimen Volume: 20 mL

Specimen Stability Information: Refrigerated (preferred)/Ambient


Specimen Type: Chorionic villi

Container/Tube: 15-mL tube containing 15 mL of transport media

Specimen Volume: 20 mg

Specimen Stability Information: Refrigerated



Specimen Type: Confluent cultured cells

Container/Tube: T-25 flask

Specimen Volume: 2 flasks

Collection Instructions: Submit confluent cultured cells from another laboratory.

Specimen Stability Information: Ambient (preferred)/Refrigerated

Specimen Minimum Volume

Blood: 0.5 mL
Amniotic Fluid: 10 mL
Chorionic Villi: 5 mg

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Varies

Clinical Information

Familial dysautonomia affects sensory, parasympathetic, and sympathetic neurons. Patients experience gastrointestinal dysfunction, pneumonia, vomiting episodes, altered sensitivity to pain and temperature, and cardiovascular problems. Progressive neuronal degeneration continues throughout the lifespan.


Variants in the inhibitor of kappa light polypeptide gene enhancer in B-cells, kinase complex-associated protein   gene (IKBKAP, also known as ELP1) cause the clinical manifestations of familial dysautonomia. The carrier rate in the Ashkenazi Jewish population is 1 in 31. There are 2 common variants in the Ashkenazi Jewish population: IVS20(+6)T>C and R696P. The carrier detection rate for these 2 variants is 99%.

Reference Values

An interpretive report will be provided.


An interpretive report will be provided.

Clinical Reference

1. Gross SJ, Pletcher BA, Monaghan KG, Professional Practice and Guidelines Committee: Carrier screening in individuals of Ashkenazi Jewish descent. Genet Med. 2008 Jan;10(1):54-56

2. Gold-von Simson G, Axelrod FB: Familial dysautonomia: update and recent advances. Curr Probl Pediatr Adolesc Health Care. 2006 Jul;36(6):218-237

3. Shohat M, Hubshman MW: Familial dysautonomia. In: Adam MP, Ardinger HH, Pagon RA, et al, eds. GeneReviews [Internet]. University of Washington, Seattle; 2003. Updated December 18, 2014. Accessed June 1, 2021. Available at

Day(s) Performed


Report Available

2 to 12 days

Test Classification

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

81260-IKBKAP (inhibitor of kappa light polypeptide gene enhancer in B-cells, kinase complex-associated protein) (eg, familial dysautonomia) gene analysis, common variants (eg, 2507+6T>C, R696P)


81265-Comparative analysis using Short Tandem Repeat (STR) markers; patient and comparative specimen (eg, pre-transplant recipient and donor germline testing, post-transplant non-hematopoietic recipient germline [eg, buccal swab or other germline tissue sample] and donor testing, twin zygosity testing or maternal cell contamination of fetal cells (if appropriate)


88233-Tissue culture, skin or solid tissue biopsy (if appropriate)

88235-Tissue culture for amniotic fluid (if appropriate)

88240-Cryopreservation (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
FDP Familial Dysautonomia, Mutation 46992-4


Result ID Test Result Name Result LOINC Value
53157 Result Summary 50397-9
53158 Result 82939-0
53159 Interpretation 69047-9
53160 Reason for Referral 42349-1
53161 Specimen 31208-2
53162 Source 31208-2
53163 Released By 18771-6


1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available in Special Instructions:

-Informed Consent for Genetic Testing  (T576)

-Informed Consent for Genetic Testing (Spanish) (T826)

2. Molecular Genetics: Biochemical Disorders Patient Information (T527) in Special Instructions

Mayo Clinic Laboratories | Genetics and Pharmacogenomics Catalog Additional Information: